Arylpyrimidines-inhibitors of platelet aggregation and bronchodilators

ABSTRACT

4-Amino-6-arylpyrimidines and salts thereof, a novel class of inhibitors of platelet aggregation and bronchodilators in mammals, and 4-hydroxy-6-arylpyrimidines as useful intermediates.

United States Patent De Angelis et al.

[ Sept. 23, 1975 ARYLPYRlMlDlNES-INHIBITORS 0F PLATELET AGGREGATION AND BRONCHODILATORS Inventors: Gerald George De Angelis, Wilton;

Hans-Jurgen Ernst Hess, Old Lyme, both of Conn.

Assignee: Pfizer, Inc., New York, N.Y.

Filed: June 19, 1973 Appl. No.1 371,420

Related U.S. Application Data Division of Ser. No. 182,220, Sept. 20, 1971, Pat. No. 3,859,288, which is a continuation-in-part of Ser. No. 78,216, Oct. 5, 1970, abandoned.

U.S. Cl. 424/251; 424/244; 424/246; 424/248; 424/250 Int. Cl. A61K 31/505 Field of Search 424/251, 248, 246, 250; 260/2564 References Cited UNITED STATES PATENTS 6/1933 Salzberg et al 260/2564 OTHER PUBLICATIONS Bredereck et al., Ber. 90 (1957), p. 942.

Von der Pla s, Rec. Trav. Chim., 84, (1965), p. 1101.

Primary ExaminerV. D. Turner Attorney, Agent, or Firm-Connolly and l-lutz [57] ABSTRACT 4-Amino-6-arylpyrimidines and salts thereof, a novel class of inhibitors of platelet aggregation and bronchodilators in mammals, and 4-hydroxy-6-arylpyrimidines as useful intermediates.

15' Claims, No Drawings CROSS REFERENcETo RELATED APPLICATIONS This application is a divisional of copending application Ser. No.-l82,220 filed Sept.-20, 1971, now US.

' Pat. No. 3,859,288, which in turn is a continuation-inpart of application Ser. No. 7 8,216, filed Oct. 5, 1970,

now abandoned. I v

BACKGROUND OF TH INVENTION This invention relates to 6-arylpyrimidines, and more particularly to a series of 4-substituted amino derivatives and salts'thereof and to theuse of said agents as inhibitors of platelet aggregation and bronchodilators in mammals, and to a series of corresponding 4- hydroxy derivatives, useful as intermediates. The invention is further concerned with 4-hydroxy-5-ethyl-6- phenylpyrimidine and its use as a bronchodilator.

The synthesis of 4-amino-6-phenylpyrimidine has been reported by Bredereck, et al., Chem. Ber., 90, 942 (1957) and by van der Plas, et al., Tetrahedron Lett., No. 3 l 2093 1964), with no disclosure of utility. The preparation, also without mention of use, of 4-amino-6- (p-t-butylphenyl)pyrimidine was reported by van der Plas, Rec. Trav. Chim.,,84, 1101 (1965).

Khromov-Borisov, Dokl. Akad. Nauk. USSR, 1180, 1129 (1968) has reported properties of 4-amino-6- methylpyrimidine with no utility disclosure.

SUMMARY OF THE INVENTlON The inhibitors of plateletaggregation of this invention are represented by the formula:

and the acid addition salts thereof, wherein:

Ar is selected from the group consisting of phenyl; monosubstituted phenyl wherein said substitutent is methyl, methoxy, 3,4-dimethoxy, hydroxy, trifluoromethyl, fluorine, chlorine, bromine, carboxy, cyano, nitro, dialkylamino said alkyl containing from 1. to 3 carbon atoms, amino or acylamino containing from 1 to 4 carbon atoms; pyridyl; thienyl; furyl; monosubstituted pyridyl, thienyl or furyl wherein said substituent is acylamino containing from I to 4 carbon atoms; naphthyl; 3-indolyl; 2- and 3-benzothienyl; and 2- and 3-benzofuryl; v f

R and R are each selected from the group consisting of hydrogen; alkyl containing from 1. to 4 carbon atoms; substituted ethyl wherein said substituent is selected from the group consisting of Z-dimethylamino;

R, and R when taken together with the nitrogen atom to which they are attached form a heterocyclic ring of the formula:

wherein Z is selected from the group consisting of CH 0, S and N-alkyl containing from 1 to 3 carbon atoms;

and n and m are integers of from 2 to 3; and

R is selected from the group consisting of hydrogen and alkyl containing from 1 to 3 carbon atoms. Of particular interest, because of their potency for inhibition of' platelet aggregation, are compounds wherein R and R are each hydrogen, alkyl up to 4 car I bon atoms and substituted ethyl where said substituent is 2-hydroxy or 2,2,2-trifluoro, Ar is phenyl or monoaggregation several compounds of the instant invention are potent relaxants of smooth muscle and in particular bronchial tissue. Of particular interest as bronchodila-' tors are congeners where R, and R are alkyl of up to 4 carbon atoms, Ar is acylamino-substituted phenyl or naphthyl and R is hydrogen or alkyl containing from 1 to 3 carbon atoms.

R is selected from the group consisting of hydrogen and alkyl containing from'l to 3 carbon atoms; and Ar is selectedfrom the group consisting of phenyl provided that when Ar is phenyLRg ethyl; substi-.

' tuted phenyl wherein said substitutent is methyl, methoxy, 3,4 dirnethoxy, hydroxy, trifluoromethyl,

fluorine, chlorine, bromine, carboxy, cyano, nitro, dialkylamino said alkyl containing from 1 to 3 carbon atoms, amino ort'acylaminocontaining from 1 to 4 carbon atoms; pyridyl; thienyl; furyl; monosub- -stituted pyridyl, thienyl or furyl wherein said substituent is acylamino containing from 1 to 4 carbon atoms; naphthyl; '3-indolyl; 2- and 3-benzothienyl;

- and 2 and 3-be'nzofuryl. ln addition to their utility as intermediates leading to the corresponding 4-arnino 6-arylpyrimidines, one of the above-mentioned 4-hydroxypyrimidines, namely,

4-hydroxy-5 ethyl-6-phenylpyrimidine, possesses unexpected activity as a relaxant of smooth muscle and in particular," bronchial tissue.

Also part of the present invention are a series of DETAILED DESCRIPTION OF THE INVENTION thetic route, Method A, is illustrated by the following scheme:

NH. Ar ArMgX [t -CH R co c u, 3 oc,,H

Ar N

l HCONH2 R, N

OH I! Ar N u Poci, N

Ra Cl 111 Ar N [I] R R NH N In the first reaction step of the aforementioned scheme, as aryl Grignard is contacted with an ester of cyanoacetate in a reaction inert solvent. In practice, the aryl Grignard, generated in situ from the aryl halide and magnesium turnings in a solvent such as ether, is treated with an ester of cyanoacetate, generally the methyl or ethyl ester, in the same solvent. It is desirable to use at least a 200% excess of the requisite Grignard reagent to effect a maximum yield of product.

The aforedescribed reaction is carried out at ambient temperatures for several hours followed by subsequent hydrolysis of the reaction mixture with dilute sulfuric acid and extraction of the amino ester into the ether phase. Removal of the solvent is followed by purification by distillation if the product (I) is an oil or recrystallization when a solid.

Alternately, an aryl lithium salt can be used in place of the Grignard reagent without markedly affecting the course of the reaction.

The requisite Grignard reagents are available commercially or can be synthesized from the corresponding aryl halide, which are commercial products, by methods available to those skilled in the art, e.g., as outlined by Kharasch, et al., Grignard Reactions of Nonmetallic Substances, Prentice-Hall, New York, 1954.

Cyclization of the B-amino arylacrylic esters (I) to the 4-hydroxy-6-arylpyrimidines (II) is carried out in a highly polar, reaction-inert solvent such as dimethylsulfoxide or dimethylformamide employing a 5 to I0 fold excess of formamide and at least two equivalents of an alkali metal lower alkoxide such as potassium tbutoxide or sodium ethoxide. Temperatures of from -I00 C. are employed with reaction times of 5-24 hours. Isolation of the desired product is carried out by pouring the reaction mixture onto ice followed by acidification with glacial acetic acid. Further purification is effected by recrystallization from a suitable solvent.

The action of halogenating agents such as thionyl chloride, phosphorous oxychloride or phosphorous pentachloride converts the 4-hydroxy-6- arylpyrimidines II) to the 4-chloro analog (III). Experimentally, II is added to a large excess of the chlorinating reagent, preferably phosphorous oxychloride, and the mixture heated to reflux from 1 to 2 hours. Lower temperature can be employed with correspondingly longer reaction times. After removal of excess reagent in vacuo, the residual product is poured into a mixture of ammonium hydroxide and ice. The crude product can be used in the next reaction or may be further purified via recrystallization.

Displacement of the 4-chloro substituent of com-- pounds of formula III, leading to the products of the present invention, is carried out in a reaction-inert solvent, e.g., ethanol or tetrahydrofuran with ammonia or an amine, HNR R wherein R and R are as previously described. Alternately, the reaction can be carried out neat, i.e., without solvent. In practice, at least 2 moles of ammonia or amino per mole of III is employed, and as much as a l0 fold excess can be employed. It is generally advantageous to heat the aforementioned reaction from about 50-l00 C. for periods of 2-8 hours. Work-up of the reaction constitutes pouring the mixture into water followed by extraction of IV into a nonaqueous solvent such as chloroform and subsequent conversion of the free base to a suitable salt, e.g., hydrochloride, by treating a solution of said base with the appropriate acid.

Method A is particularly applicable to the preparation of compounds of formula IV wherein R R and R are as previously described and where Ar is pyridyl, thienyl, furyl, naphthyl, 3-indolyl, 2- and 3-benzothienyl, 2- and 3-benzofuryl, phenyl and monosubstituted phenyl where said substituents are methyl, methoxy, 3,4-dimethoxy, trifluoromethyl, fluorine, chlorine and bromine.

Also within the purview of this invention are congeners of IV wherein Ar includes 3,4- methylenedioxyphenyl, acetylphenyl and disubstituted phenyl where the second substituent is selected from the group consisting of methyl, methoxy, fluorine, chlorine, bromine and ethoxy.

The first alternate series of reactions, Method B, leading to the products of the present invention, is outlined as follows:

+ Nascit 00 CH 0 n v HCNHZ VI PL'JCl VII HNR R VIII Raney Nickel In the first reaction of the aforementioned Method B is appropriately substituted o-chlorobenzonitrile is contacted with a salt of a lower alkyl thioglycolate ester in a reaction-inert solvent; In practice, sodium methyl thioglycolate, prepared by treating methyl thioglycolate with an equivalent amount of sodium alkoxide in a lower alkanol solvent followed by removal of the solvent in vacuo, is added to a reaction-inert solvent, preferably of moderately high polarity, e.g., dimethylformamide or hexamethylphosphoramide. The resulting solution or suspension of sodium methyl thioglycolate is treated with an equimolar amount of the requisite ochlorobenzonitrile dissolved in the same solvent.

Altemately, the sodium salt of the methyl thioglycolate can be generated in situe in said reaction employing either an equimolar amount of sodium hydride or a sodium alkoxide.

The aforedescribed reaction is carried out at 50-l00 C. for a period of 15 minutes to 2 hours. A

convenient method of isolation is to cool the reaction mixture and subsequently add it to a mixture of ice and water. The desired product can be filtered, dried, and recrystallized from a suitable solvent.

The requisite o-chlorobenzonitriles are available commercially or can be synthesized by one skilled in the art, e.g, by the method of Nakaoka, et al., German Pat. No. 1,230,026 (CA. 66, 55255e).

Cyclization of the 2-carbomethoxy-3-aminobenzothiophenes (V) to the tricyclic 4-hydroxybenzothieno[3,2-d]pyrimidines (VI) is carried out in a reaction-inert solvent such as dimethylsulfoxide or dimethylformamide using a 5 to fold excess of formamide and an equimolar amount of an alkali metal lower alkoxide such as sodium methoxide or potassium tbutoxide. Reaction temperatures of 75l00 C. are employed with a reaction time of 30 minutes to 2 hours. The desired product is isolated by pouring the cooled reaction mixture into water followed by acidification with acetic acid, filtration and drying. The product can be further purified by trituration or recrystallization from a suitable solvent.

The action of halogenating agents, e.g., thionyl chloride, phosphorous oxychloride or dichlorophenylphosphine oxide converts the 4-hydroxybenzothieno[3,2- d]pyrimidines (VI) to the corresponding 4-chloro analogs (VII). In practice, VI is added to a large excess of the appropriate reagent, preferably phosphorous oxychloride, and the mixture heated. Reflux temperatures are preferred, although lower temperatures may be employed with correspondingly longer reaction times. The reaction period is not critical, but will vary with temperature, concentration and reactivity of the starting reagents. In general, a period of from about 2 to about 8 hours is operable. A convenient method of isolation comprises removal of the excess phosphorous oxychloride in vacuo followed by treatment of the residue with water and sufficient ammonium hydroxide solution to render the solution basic. The resulting product is filtered and air dried. It can be used in this crude state for subsequent reaction or can be recrystallized from an appropriate solvent.

Displacement of the 4-chloro substitutent of compounds of formula VII, leading to VIII, is effected in a reaction-inert solvent with ammonia or an amine, HNR R wherein R and R are as previously described. In practice, a mixture of the appropriately substituted 4-chlorobenzothieno[3,2-d]pyrimidien and ammonia or a suitable amine are heated in a solvent such as ethanol, dimethylformamide, benzene or tetrahydrofuran. It is advantageous to employ at least 2 moles of amine per mole of halide, and as much as a 10 fold excess can be employed. It is generally desirable to heat the aforementioned reaction mixture to temperatures from about 40l50 C., with a preferred range of 75-l00 C. Reaction times are not critical, and will vary with reaction temperature, molar quantities of reactants, etc. In general, periods of l to 6 hours are operable.

Isolation of the products following the aforedescribed reaction is most conveniently carried out by diluting with water followed by extraction with a water immiscible solvent, e.g., chloroform, ether or benzene. The separated, non-aqueous phase is then dried over a suitable drying agent and the solvent removed in vacuo.

The final reaction of Method B, leading to the products of the present invention, comprises desulfurization of the 4-aminobenzothieno[3,2-d]pyrimidines (VIII) using an excess of Raney nickel. Experimentally, the reaction is carried out in a highly polar, reaction-inert solvent such as dimethylformamide and at temperatures of l25l50 C. Reaction times are not critical,.

but the preferred range is from 2448 hours. Removal of the spent Raney nickel followed by concentration of the filtrate to dryness provides the crude free base of the desired product, which is converted to hydrochloride salt by conventional methods. Products isolated by Method B prove to be identical with those synthesized by Method A.

The aforedescribed method is particularly useful for the preparation of products of the instant invention wherein R and R are as previously described, R is hydrogen and Ar is phenyl and monoor disubstituted phenyl where said substituent is methyl, methoxy, 3,4- dimethoxy, cyano or carboxy.

The third alternate approach to the synthesis of compounds of the present invention (Method C) is outlined in the following scheme:

Ar N SH TQM R3 Ar N Rl Rz The initial step in the reaction sequence of Method C is a condensation of a (lower)alkyl aroylacetate with thiourea resulting in the formation of a 4-hydroxy-2- mercapto-6-arylpyrimidine (IX). In practice, the requisite B-ketoester is contacted with approximately equimolar amounts of thiourea in a reaction-inert solvent such as those represented by the (lower)alkanols. Temperatures of 90 C. are operable with corresponding reaction times of about 96-140 hours. Isolation of the desired product is achieved by concentration of the reaction mixture in vacuo followed by dilution with water, acidification to pH 3, cooling and, finally, filtration of the crude solids.

Alternately, S-methylisothiourea may also be employed in place of urea in the above described reaction and provides the corresponding 2-methylthio analog of IX.

The aroylacetates are either commercial products or can be conveniently synthesized by methods available to those skilled in the art, e.g., according to those extensively outlined by Hauser, et al., in Organic Reactions, John Wiley & Sons, Inc., New York, 1954,

Chapter 9, page 266. Aroyl-q-substituted-acetates, Ar- COCl-l(R )CO C l-l are synthesized according to the procedure as taught by Hope, et al., J. Chem. Soc., 95,

Desulfurization of IX in aqueous sodium hydroxide using Raney nickel results in the formation of the corresponding 4-hydroxy-6-arylpyrimidine (II), identical to that prepared by Method A. Similarly, when the corresponding S-methyl analog of 1V is employed, identical products are obtained.

The subsequent steps of the reaction sequence, Method C, and corresponding results are identical to those of Method A.

Method C is especially useful for the preparation of compounds of the instant invention where R R and R are as indicated previously and where Ar is phenyl or monoor disubstituted phenyl said substituents being cyano, methyl, methoxy, carboxy, acylamino or dialkylamino, pyridyl, furyl and acylamino substituted pyridyl and furyl, 3-indolyl, naphthyl and 2- and 3- benzofuryl.

Further, the use of an a-alkylaroylacetate in the initial reaction of Method C allows the synthesis of S-alkyl congeners of the final products (IV). Substitution of acetamidine or propionamidine' for thiourea leads to analogs of IV bearing a 2-methyl or Z-ethyl substituent.

Introduction of a nitro substituent into the aryl moiety of the 4-amino-6-arylpyrimidines can be carried out by direct nitration employing a mixture of nitric and sulfuric acids. In practice, to a solution of thesubstrate in concentrated sulfuric acid is added, dropwise' and at room temperature, nitric acid. The resulting reaction is carried out at ambient temperatures for about 2-6 hours. The reaction is quenched with ice, made basic with ammonium hydroxide and the free base extracted into a water immiscible solvent such as chloroform or methylene chloride.

In general, more than one nitroisomer is formed as a result of direct nitration. These isomers can subsequently be separated by conventional methods known to those skilled in the art, e.g., by fractional crystallization or column chromatography. Identification of said isomers is most conveniently carried out using nuclear magnetic resonance studies.

Treatment of the aforedescribed nitro compounds with reducing agents, such as stannous chloride and hydrochloric acid, results in the preparation of the corresponding amino analogs. Stannous chloride reductions are carried out at temperatures of 40-75 C. with reaction times of 2 to 4 hours, and preferably employ 12N hydrochloric acid. Thev product, which is frequently sparingly soluble as the dihydrochloride salt in .l 2N hydrochloric acid, is filtered from the cooled reaction mixture and the free base liberated by treatment of the salt with an aqueous base such as sodiumhydroxide solution. I

In addition to the aforementioned method of reducing nitro substituents, several other reducing reagents, known to those skilled in the art, can be employed with comparable results, e.g., tin-hydrochloric acid, 'hdyrogenplatinum oxide, or aluminum amalgam. I

4-Amino-6-aminoarylpyrimidines, resulting from the above-mentioned reduction of the corresponding nitro compounds, can subsequently be reacted with a wide variety of reagents, including alkanoyl halides, anhydrides, alkyl halides, sulfonyl halides, isocyanates and thioisocyanates.

I Reaction of said amino compounds with alkanoyl halides and alkoxycarbonyl halides leads to the preparation of the corresponding acylamino and alkyl carbamates, respectively'ln practice, the alkanoyl or alkoxycarbonyl halide is added dropwise to a mixture of the appropriate amino compound and an alkali metal carbonate in a suitable reaction-inert solvent such as benzene, ether or methylene chloride. The reaction is preferably carried out at ambient temperatures for a reaction period of about 12 to 24 hours. Hydrolysis of the reaction with water'and separation of the water immiscible solvent leads to the subsequent isolation of the crude product. I

Analogously, sulfonyl halides are reacted under similar conditions and give rise to the corresponding sulfonamides.

Formation of acylamino substituents employing simple anhydrides or mixed anhydrides in place of aroyl or alkanoyl halides can be carried out with equal ease. Experimentally, the amino compound is contacted with at least an equimolar amount of the requisite anhydride and preferably a 20-50% excess. A solvent, such as benzene, pyridyne, chloroform or tetrahydrofuran, can

be employed, or the reaction can be run neat, i.e., with-' out solvent. In the latter case it is desirable to use as much as a IOU-300% excess of the appropriate anhydride. Said reaction is carried out for 12 to 24 hours at ambient temperatures. The excess anhydride can be removed under reduced pressure and the residue dissolved in ethyl acetate after which it is converted to the desired salt or alternately, the original reaction mixture can be diluted with ethyl acetate and the salt prepared directly by conventional methods.

Reaction of 4-amino-6-aminoarylpyrimidines with isocyanates and isothiocyanates gives rise to the corresponding ureas and thioureas. Said reactions are effected with the appropriate amino substrate and an equimolar amount, plus as much as a 20% excess, of the requisite isocyanate or thioisocyanate in a reactioninert, solvent, e.g., ether, tetrahydrofuran or benzene. Reaction times of about 12 to 24 hours at room temperature are generally adequate. Isolation of the desired product is achieved by removal of the solvent under reduced pressure followed by recrystallization of the residue from a suitable solvent.

Synthesis of 6-( N-alkylaminoaryl)pyrimidines and 6-(N,N-dialkylaminoaryl)pyrimidines is conveniently .halides and aralkyl halides can also be used with similar ease.

In practice, a solution or suspension of the aminoarylpyrimidine and at least an equimolar amount of an alkali metal carbonate is treated. with the appropriate alkyl halide, preferably the iodide, in the amounts previously described. The solvents for this alkylation can vary in nature and are selected from the group including (lower)alkanols, N,N-di(lower)alkyl(lower)alkylcarboxamides, cyclic ethers and water. Elevated temperatures of from 50-1 10 C. are employed, with reaction times of l-8 hours. The product is isolated by evaporation of the reaction solvent in vacuo followed by extraction of the residue with such solvents as methylene chloride or chloroform or, alternately, when water is used as the reaction solvent the product can be extracted from the mixture directly using said solvents. The separated extracting solvent is evaporated to dryness and the crude product purified by recrystallization from a suitable solvent or chromatographing on a silica gel column.

Also considered within the scope of the present invention are congeners wherein R, and R when considered together with the nitrogen atom to which they are attached form a piperazine ring of the formula where X is (lower)alkyl, (lower)alkoxy, (lower)alkyleneoxy, phenyl, furyl, thienyl, di(lower)alkylamino, l-piperidyl and ar(lower)alkyloxy.

As has been previously noted, compounds of the instant invention can form acid addition salts. Basic compounds of the present invention are converted to the acid addition salts by interaction of the base with an acid either in an aqueous or non-aqueous medium. In a similar manner, treatment of the acid addition salts with an aqueous base solution, e.g, alkali metal hydroxides, alkali metal carbonates and alkali metal bicarbonates or with a metal cation which forms an insoluble precipitate with the acid anion, results in a regeneration of the free base form. Such conversions are best carried out as rapidly as possible and under temperature conditions and method dictated by the stability of sad basic products. The bases thus regenerated may be reconverted to the same or a different acid addition salt.

In the utilization of the chemotherapeutic activity of those compounds of the present invention which form salts, it is preferred, of course, to use pharmaceutically acceptable salts. Although water-insolubility, high toxicity, or lack of crystalline nature may make some particular salt species unsuitable or less desirable for use as such in a given pharmaceutical application, the water insoluble or toxic salts can be converted to the corresponding pharmaceutically acceptable bases by decomposition of the salt as described above, or alternately they can be converted to any desired pharmaceutically acceptable acid addition salt.

Examples of acids which provide pharmaceutically acceptable anions are hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, or sulfurous, phosphorous, acetic, lactic, citric, tartaric, succinic, maleic, and gluconic.

The terminal complication of thrombus formation in ischaemic heart disease, cerebral vascular disease, legvein thrombosis, pulmonary embolism and peripheral vascular disease is well documented in the medical literature, and has recently been reviewed by Mustard, et al., Pharm. Rev., 22, 97 (1970). The causal role of platelet aggregation in the formation of thrombi, which are masses of agglutinated platelets and leucocytes as distinguished from clots in which the elements of the blood are randomly distributed, has bee postulated by many medical studies and has been reviewed by Mustard, et al. The compounds of the instant invention mediate their remarkable antithrombogenic activity through their ability to inhibit the aforementioned platelet aggregation.

As previously indicated, the 4-amino-6- arylpyrimidines of the present invention are all readily adapted to therapeutic use as inhibitors of platelet aggregation. Typical member compounds of interest in diethylamino-S-methyl-6-phenylpyrimidine and 4- diethylamino-5-ethyl-6-phenylpyrimidine.

in addition to their usefulness as inhibitors of platelet aggregation, several congeners of this series show outstanding potency as smooth muscle relaxants and in particular as bronchodilators. Compounds notable for this therapeutic usefulness include 4-diethylamino-6- (m-acetylaminophenyl)pyrimidine, 4-diethylamino-6- (m-isobutrylaminophenyl)pyrimidine, 4-diethylamino-- 6-(m-propionylaminophenyl)pyrimidine, 4-di-npropylamino-6-( m-acetylaminophenyl)-pyrimidine and 4-diethylamino-6-(p-acetylaminophenyl)pyrimidine.

The 4-hydroxy-6-arylpyrimidines of the present invention, as previously mentioned, are useful intermediates leading to the synthesis of the corresponding 4-amino-6-arylpyrimidines. In addition, it has been found that at least one of these intermediates, 4- hydroxy-Sethyl-6-phenylpyrimidine, has unexpected, outstanding activity as a bronchodilator. It is especially interesting, since the corresponding analogs wherein R is hydrogen, methyl and propyl have considerably less activity.

The 4-amino-6-arylpyrimidines and 4-hdyroxy-5- ethyl-6-phenylpyrimidine and the pharmaceutically acceptable salts thereof, which are useful as inhibitors of platelet aggregation and/or bronchodilators in mammals, may be administered either as individual therapeutic agents or as mixtures of thereapeutic agents. They may be administered alone, but are generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice. For example, they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, aqueous suspensions or solutions, injectable solutions, elixirs, syrups and the like. Such carriers include solid diluents, or filters, sterile aqueous media and various nontoxic organic solvents. Moreover, the oral pharmaceutical compositions of this invention may be suitably sweetened and flavored by means of various agents of the type commonly used for this purpose.

The particular carrier selected by the proportion of active ingredient to the carrier are influenced by the solubility and chemical nature of the therapeutic compounds, the chosen route of administration and the needs of the standard pharmaceutical practice. For example, where those compounds are administered orally in tablet form, excipients such as lactose, sodium citrate, calcium carbonate and dicalcium phosphate may be used. Various disintegrants such as starch, alginic acids, and certain complex silicates together with lubricating agents such as magnesium stearate, sodium lauryl sulphate and talc, may also be used in producing tablets for the oral administration of these compounds. For oral administration in capsule form, lactose and high molecular weight polyethylene glycols are among the preferred materials for use as pharmaceutically acceptable carriers. Where aqueous suspensions are to be used for oral administration, the compounds of this invention may be combined with emulsifying or suspending agents. Diluents such as ethanol, propylene glycol, glycerine and their combinations may be employed as well as other materials.

For purposes of parenteral administration and inhalation, solutions or suspensions of the instant compounds in sesame or peanut oil or in aqueous propylene glycol solutions can be employed, as well as sterile aqueous solutions of the soluble acid addition salts described hereinafter. These particular solutions are especially suited for intramuscular and subcutaneous injection purposes. The aqueous solutions, including those of the acid addition salts dissolved in pure distilled water, are also useful for intravenous injection purposes provided that their pH is properly adjusted beforehand. Such solutions should also be suitably buffered, if necessary, and the liquid diluent first rendered isotonic with sufficient saline or glucose.

The compounds may be administered to subjects suffering from bronchoconstriction by means of inhalators or other devices which permit the active compounds to come into direct contact with the constricted areas of the tissues of the subject. When administered by means of a spray formulated as a 1% solution, utilization several times a day is preferred.

Itis necessary that the active ingredient form a proportion of the composition such that a suitable dosage form will be obtained. Obviously, several dosage unit forms may be administered at about the same time. Although compositions with less than 0.005% by weight of active ingredient might be used in certain instances, it is preferred to use compositions containing not less than 0.005% of the active ingredient; otherwise the amount of carrier becomes excessively large. Activity increases with the concentration of the active ingredient. The composition may contain 10, 50, 75, 95 or an even higher percentage by weight of the active ingredient.

Although the use of the present invention is directed toward the treatment of mammals in general, the preferred subject is humans. In determining an efficacious dose for human therapy, results of animal testing are frequently extrapolated and a correlation is assumed between animal test behavior and proposed human dosage. When a commercially employed standard is available, the dose level of the clinical candidate in humans is frequently determined by comparison of its performance with the standard in an animal test. For example, theophylline is employed as a standard bronchodilator and is administered to humans at the rate of 150 to 300 mg. every 4 hours. It is assumed, then, that if compounds of the present invention have activity comparable to theophylline in the test assay, that similar doses will provide comparable responses in humans.

Obviously, the physician will ultimately determine the dosage which will be most suitable for a particular .individual, and it will vary with the age, weight and response of the particular patient as well as with the nature and extent of the symptoms and the pharmacodynamic characteristics of the particular agent to be administered. Generally, small doses will be administered initially, with a gradual increase in the dosage until the optimum level is determined. It will often be found that when the composition is administered orally, larger quantities of the active ingredient will be required to produce the same level as produced by a small quantity administered parenterally.

Having full regard for the foregoing factors it is considered that an effective daily dosage of the compounds of the present invention in humans of approximately 50-750 mg. per day, with a preferred range of about 50-35O mg. per day in single or divided doses, or at about 1 to 7 mg./kg. of body weight will effectively prevent thrombus formation in human subjects prone to said disorder, and alleviate bronchoconstriction. These values are illustrative, and there may, of course, be individual cases where higher or lower dose ranges are merited.

The following examples are provided solely for the purpose of illustration and are not to be construed as limitations of this invention, many variations of which are possible without departing from the spirit or scope thereof.

EXAMPLE 1 4-Diethylamino-6-phenylpyrimidine hydrochloride Method A A. Ethyl- 2-aminocinnamate (I; Ar C H To a solution of day ethyl ether (300 ml.) is added magnesium turnings 16.9 g.). Bromobenzene 103 g.) in ether (600 ml.) is added at a rate to maintain gentle refluxing (Aniodine crystal or a ml. of methyliodide often must be added to initiate the reaction) Refluxing is continued until most of the magnesium has reacted. Ethyl cyanoacetate (30 g.) is added over a 30 minute period and the reaction mixture allowed to stir for 3 hours at'room temperature after which time 3.5 N sulfuric acid'(l80 ml.) is added and the reaction allowed to stir'for 30 additional minutes. The aqueous layer is extracted with diethyl ether and the organic layer washed with water and dried over sodium sulfate. Removal of the ether in vacuo followed by distillation of the residual oil gives the desired product, b.p. at 0.4 mm, 138l42C.

B. 4-Hydroxy-6 phenylpyrimidine (II; Ar C H R To a mixture of ethyl 2-aminocinnamate (54 g.; 0.28 mole) and formamide (100 ml.) in dimethylsulfoxide (700 m1.) at 100C. is added via a dropping funnel potassium t-butoxide (63 g.; 0.56 mole) in 300 ml. of the same solvent over a 15 minute period. The solution is stirred for 16 hours at 100 C. after which time it is cooled, poured over ice (2 l.) and acetic acid added to complete precipitation. The solid obtained upon filtration is washed with water, isopropyl alcohol and air dried, 30 g., m.p. 266-267 C.

C. 4-Chloro-6-phenylpyrimidine (Ill: Ar C l-l R H) 4Hydroxy-6-phenylpyrimidine (2.1 g.) is added to phosphorous oxychloride (60 ml.) and refluxed for 1.5 hours. Excess phosphorous oxychloride is removed in vacuo, and the dark oil poured over concentrated ammonium hydroxide/ice. The precipitate which forms is filtered, washed with water and dried, 2.1 g., m.p. -98 C.

D. 4-Diethylamino--phenylpyrimidine hydrochloride (IV; Ar C H R R C H R H) A mixture of 4-chloro-6-phenylpyrimidine (10.0 g.), diethylamine (7.5 g.) and ethanol (200 ml.) is refluxed for 5 hours. At the end of this time the reaction mixture is poured into water (800 ml.) and extracted with chloroform. The chloroform layer is dried and concentrated in vacuo to an oil which is taken up in methanol, treated with activated charcoal, filtered and the methanol removed in vacuo. The residual oil is taken up in diethyl ether and anhydrous hydrogen chloride bubbled into the solution until precipitation is complete. Filtration yields the hydrochloride salt (6.45 g.) which is recrystallized from ethanol/hexane to yield a tan microcrystalline solid, 5.0 g., m.p. 214215 C.

Anal. Calcd. for C H N .HCl: C, 63.7; H, 6.9; N, 15.9. Found: C, 63.6; H, 7.0; N, 15.7.

EXAMPLE II 4-Diethylamino-6-phenylpyrimidine hydrochloride Method B A. 2-Carbomethoxy-3-aminobenzothiophene (V; X H) To a solution of t-butyl alcohol (30 ml.) and potassium t-butoxide (1.12 g.; 0.01 mole) is added via a dropping funnel methyl thioglycolate (1.06 g.; 0.01 mole) in t-butyl alcohol ml.). The solution is stirred for 10 minutes and then concentrated in vacuo to yield the sodium salt of methyl thioglycolate, which is taken up in 30 ml. of dimethylformamide. To this is added via a dropping funnel 2-chlorobenzonitrile (1.37 g.; 0.01 mole) in dimethylformamide (10 ml.), and the solution is warmed to 75 C. for 30 minutes. At the end of this time the solution is cooled and poured onto 200 ml. of ice and water. The resultant precipitate is filtered, washed with water and dried to yield a white microcrystalline solid, 1.8 g., m.p. 105-106 C.

B. 4-l-lydroxybenzothieno[3,2-d]pyrimidine (V1; X H) To a solution of 2-carbomethoxy-3-aminobenzothiophene (2.07 g.; 0.02 mole) and potassium t-butoxide (2.24 g.; 0.02 mole) in dimethylsulfoxide (30ml.) is added an excess of formamide (ca 5 ml./g. of 2- carbomethoxy-3-aminobenzothiophene). This is heated to 90 C. until the reaction is complete as evidenced by thin layer chromatography (-30 minutes). The solution is cooled, poured into water, acidified with glacial acetic acid and the resultant solid is filtered. Washing with isopropyl alcohol and then ether yields a white solid, 1.76 g., m.p. 300301 C.

C. 4-Chlorobenzothieno[3,2-d]pyrimidine (V11; X

A mixture of 4-hydroxybenzothieno[3,2- d]pyrimidine (20 g.; 0.1 mole) in phosphorous oxychloride (500 ml.) is refluxed with stirring for 4 hours. At the end of this timethe solution is cooled and concentrated in vacuo to a brown semisolid, which is poured into 250 g. ice/250 ml. ammonium hydroxide solution. The resultant solid is filtered and air dried to yield a beige microcrystalline solid, 19.7 g., m.p. 139-140 c.

D. 4-Diethylaminobenzothieno[3,2-d]pyrimidine hydrochloride (V111; X H; R R C H A mixture of 4-chlorobenzothieno[3,2-d]pyrimidine (15 g.; 0.068 mole) and an excess of diethylamine in ethanol (500 ml.) is refluxed with stirring for 3 hours. The solution is cooled, poured into water (500 ml.) and extracted with chloroform. The chloroform extracts are washed with water, dried over sodium sulfate and the chloroform removed in vacuo to yield a dark oily residue. This is taken up in methanol, treated with activated charcoal, filtered, and the solvent removed in vacuo to yield an oily residue which is taken up in diethyl ether. Anhydrous hydrogen chloride gas is bubbled into this solution until precipitation ceases. Filtration yields the hydrochloride salt, 13.4 g., m.p. 226230 C.

E. 4-Diethylamino-6-phenylpyrimidine hydrochloride (IV; X H; R R C H To a solution of 1.5 ml. of dimethylformamide containing 4-diethylaminobenzothieno[3,2-d]pyrimidine (2.0 g.) is added a large excess of Raney nickel and the resulting mixture heated to reflux. Water is allowed to distill from the reaction mixture until the temperature reaches 150 C. where refluxing is continued with rapid stirring for 48 hours. The solids are filtered and the filtrate concentrated in vacuo to an oil. The residual oil is partitioned between water and chloroform and the organic layer separated and dried over sodium sulfate. Removal of the solvent under reduced pressure provides an oil which when dissolved in ethyl ether and treated with gaseous hydrogen chloride provides 1.4 g. of the hydrochloride salt of the desired product, which is identical in every respect to that synthesized via Method A.

EXAMPLE lll 4-Diethylamino-5 -ethyl-6-phenylpyrimidine Hydrochloride Method C A. 2-Mercapto-4-hydroxy-6-phenylpyrimidine (V; Ar s s; 3 z s) A reaction vessel is charged with 750 ml. of dry ethanol, g. (0.36 mole) of ethyl a-benzoylbutyrate, 39.3 g. (0.72 mole) of sodium methoxide and 49.3 g. (0.82 mole) of thiourea. The reaction mixture is heated to the reflux temperature (79 C.) and stirred at that point for hours. The resulting reaction mixture is concentrated in vacuo to a low volume and the thick slurry then diluted with 400 ml. of water and ice. The aqueous solution is chilled to 10 C. and then acidified to pH 3.0 by the slow addition of concentrated hydrochloric acid. The crystalline slurry is granulated for 30 minutes at 20 C. and then filtered. The cake is washed with warm water (60 1. at 35 C.) and then dried, 35.8 g., m.p. 233236 C.

B. 4-Hydroxy-5-ethyl-6-phenylpyrimidine (11; Ar C6H5; R3 C2H5) To a solution of 283 ml. of water containing 1 1.4 g. of sodium hydroxide and 35 g. of 2-mercapto-4- hydroxy-S-ethyl-6-phenylpyrimidine, under a nitrogen atmosphere and heated to 65 C. is added 265 g. of Raney Nickel in small portions. After heating for 2 hours on a steam bath, an additional 80 g. of Raney Nickel is added. After an hour the desulfurization is complete and the reaction mixture is cooled. The Raney Nickel is filtered, the filtrate is concentrated in volume in vacuo and diluted with ice and water. The aqueous solution is acidified to pH 5.0 with concentrated hydrochloric acid and stirred for 15 minutes. The resulting precipitate is filtered and dried, 22.1 g.; m.p. 180-182 C. The analytical sample is recrystallized from chloroform-hexane.

of 4-hydroxy-5 -ethyl-6- phenylpyrimidine in 250 ml. of phosphorous 'oxychloride is stirred and heated to the reflux temperature (lO-l 10 C.). At 78 C. all of the solid materials are dissolved, and the solution then is stirred at 1 10 C. for 24 hours. The solution is concentrated in vacuo to a volume, and then carefully added at 50 C. to a mixture of concentrated ammonium hydroxide and ice. The precipitate is filtered and theoff-white solid is air dried, 21.5 g., m.p. 46-47 c. I I 7 Anal. Calcd. for C H CIN C, 65.9; H, 5.1; N, 12.8. Found: C, 65.2; H, 4.9; N, 12.6.

D. 4-Diethylamino-S-ethy1 6-pheny1pyrimidine hydrochloride (1V; Ar C H R3 CH An ethanol solution of 12 g. of 4-chloro-5-ethy1-6- v phenylpyrimidine and 16.1 g. of diethylamine is stirred at the reflux temperature overnight. The ethanol and excess amine are removed in vacuo to provide the residual product as a thick oil. The oil is dissolved in chloroform which is subsequently washed twice with water, dried over sodium sulfate and decolorized with charcoal. The chloroform is removed under reduced pressure, the residual oil taken up in ethyl acetate and dry hydrogen chloride gas added until the precipitate ceases to form. The product is filtered and dried, 6.9 g., m.p. 138-139.5 C. y

The analytical sample was prepared by recrystallization.

Anal. Calcd. for C. H C1N C, 65.9; H, 7.6; N, 14.4. Found: C, 66.1; H, 7.6; N, 14.4.

EXAMPLE IV The procedures of Example 1 are repeated, using the appropriately substituted starting materials, to provide the following compounds in good yields:

-Continued R1 3 -P-, Procedure n-C H "-C4Hg H 90- 91 Exumplel i-C H 1 C Hg H 103-104 Example 1 CgH5 C H CH 201-2025 Example 111 iC; H t--C5H CH 210-212 Example 111 CH CH CQHS 163-166 Example 111 i-C H iC;,H-, C H 75- 78 Example 111 CH CH nC H 165-166 Example 111 2 5 C H nC;,H 132-134 Example 111 C H cgH5 1C 1'l 95- 97.5 v Example 111 EXAMPLE V 4-( 1-Pyrrolidinyl) -6-phenylpyrimidine hydrochloride, m.p. 266268 C.; 4-( 1 Piperidyl )-6-phenylpyrimidine hydrochloride,

m.p. 278280 C.;

4-( l-Hexahydroazepinyl)-6-pheny1pyrimidine hydrochloride, m.p. 65 C.;

4-(4-Morpholinyl)-6-phenylpyrimidine hydrochloride, m.p. 259260 C.;

4-(4-Methyl-1-piperazinyl)-6-phenylpyrimidine hydrochloride, m.p. 290-292 C. (decomposition).

v EXAMPLE V1 Again, employing the procedures of Example 1, and utilizing the appropriate starting reagents, the following congeners are prepared:

4-(2,2,2-Trifluoroethylamino)-6-phenylpyrimidine hydrochloride, m.p. 195197 C.;

4-[Ethyl(2,2,2-trifluoroethyl)amino]-6- phenylpyrimidine hydrochloride, m.p. 208-2l0 C.;

4-[2-( Diethylamino)ethylamino]-6- phenylpyrimidine hydrochloride, m.p. 8082 C.;

4-[Methyl(2-hydroxyethy1)amino]-6- phenylpyrimidine hydrochloride, m.p. 204-205 C.;

4-[Ethyl(2-hydroxyethy1)amino]-6- phenylpyrimidinehydrochloride, m.p. l82-184 C.; 4-[ Bis( 2-hydroxyethyl )amino] -6-pheny1pyrimidine hydrochloride, m.p. l53-l55 C.;

4-( Diallylamino)-6-phenylpyrimidine hydrochloride,

1 m.p.,273275C.; w 4-(3-Pyridylmethylamino)-6-phenylpyrimidine dia hydrochloride, m.p. 225-226 c.; 3 4-[Methyl(3-pyridylmethy1)amino]-6- '/N\ I phenylpyrimidine dihydrochloride, m.p'. 262 266 C.; RI Ethyl N-( 6-phenyl-4-pyrimidinyl)anthranilate hydro- I o P i chloride, m.p. -170 C.; H 4-Diethy1amino-5-ethy1-6:( 2-naphthyl)pyrimidine H CH H 218-220 Examplel hydrochloride, m.p. 16l-l62 C.;; H CH5 H -192 Examplel 4-Diethy1amino-5-ethyl-6-(4-to1y1)pyrimidine hydro- E ,"Iifi 15:12,; I chloride, m.p. 103.104 H n-C H,, H 142-145 Example 1 H 1C |H9 H 138-140 Example] 55 EXAMPLE VII 2 74 E I 1 2 H, EH, 2 220-22; E2125]: Utilizing the ammation procedure of Example l-D or Cl- Ii 2C=H1 g f pi 111-D, and employing the" appropriate 4-ch1oro-6- 22 6 H 1325: I phenylpyrimidine and the requisite amine, the follown-C H nC;H H 152-154 Examplel mg congeners are synthesized:

R1 R2 R3 R1 R2 R3 cyclo CJH, H- H cyclo C H HO(CH2)2 n-C H-,

cyclo C,H, CH;, H cyclo C H HO(CH2)2 H In ,a similar manner are prepared 4-diethylamino-6- (3,4-dimethoxyphenyl)pyrimidine hydrochloride, m.p. 199.520l C., and 4-diethylamino-6-(3-ethoxy-4- methoxyphenyl)pyrimidine, m.p. 2182l9 C.

EXAMPLE XII Follwing the experimetnal details of Example I or III, and starting with the appropriately substituted reagents, the following compounds are prepared:

EXAMPLE XIII 4-Diethylamino-6-( p-hydroxyphenyl )pyrimidine hydrobromide A solution of 18.6 g. (0.1 mole) of 4-diethylamino-6- (p-methoxyphenyl)pyrimidine in 30 ml. of 48% hydrobromic acid and 30 ml. of glacial acetic acid is heated to the reflux temperature and gaseous hydrogen bromide slowly introduced below the surface during the first 2 hours of refluxing. Heating is continued until thin layer chromatography indicates the reaction is complete. The reaction is cooled and the excess acetic acid and hydrobromic acid are removed under reduced pressure. The residual product is triturated with acetone, filtered and recrystallized from ethanol/hexane.

EXAMPLE XIV Following the procedure of Example XIII and starting with the 6-(methoxyphenyl)pyrimidines of Example XII and the appropriate reagents the following analogs are prepared:

EXAMPLE XV The method of Example III is repeated, using the requisite starting reagents, to provide the following congeners in moderate yields:

EXAMPLE XVI 4-Diethylamino-6-(m-nitrophenyl)pyridimine hydrochloride To a solution of 1.0 g. (3.8 m moles) of 4- diethylamino-o-phenylpyrimidine hydrochloride in ml. of concentrated sulfuric acid is added 10 ml. of nitric acid dropwise at room temperature. The reaction mixture is allowed to stir for 6 hours, and is then R 3 N poured onto ice and made basic with concentrated ammonium hydroxide. The product is extracted into chlo- 2 roform, and the organic layer dried over sodium sulfate X R R R and concentrated in vacuo to an oil. The residual oil is dissolved Il'l ethyl acetate and hydrogen chloride slowly g-ggfi E35 g 3 introduced into the solution until the precipitation is I Z CH3 complete. The hydrogen chl oride salt is filtered, dried 2CO H CH i-C H H and recrystallized, mp. 238 240 C. figs E CH3 CH3 Anal. Calcd. for C H O N HCl: 0, 54.5; H, 5.6; N,

H CH H l 2 CN c H c C2115 18.2. Found. C, 54.1, H, 5.6, N, 18.0. 2 CN 2 s 22 H 3C.O2H z)s H 3CO2H H CH3 H 3-CO H H0(CH C H H 4-CO:H CF CH: Cir: cH EXAMPLE 4 co,H CF CH cH H 4 -C0,H C H iC H, H Z:g8=g :ggg g E The nitration procedure of Example XVI is repeated, CH3 ,5 CSH CzH5 using the appropriate starting reagents, to provide the C 2 3 cyclo s u H following analogs in good yields:

R1 R2 3 R1 R2 R:

H C,H H CF CH H H H lC;,H-, H CFQCHZ C2H5 H H I\C4H9 H H (C a)2 z)2 H CH CH H CH HO(CH,) H CH3 nC;,H H C H HO(CH H z s a -1 H CH3 cyclo C H H n-C;,H nC H H HO(CH2)- cyclo C3H5 H H=)4 H H0(CH,),- HO(CH H (CH2)=. H CH =CHCH CH =CHCH, H 2)s H H 2-HO2CC6H4 H )z0(CH=)2 H H z-H Nso c H, H 2)2 3)(CH2)2 H CH3 cyclo CJH, CH3 pz s C2H5 CH3 CH3 cyclo CBHH C H, 1-C H, |-C;,H-, CH CH =CHCH cyclo C,,H CH, CH3 CH3 CH5 C2H5 Ca -l5 2 s CH3 CH3 nC H 3 CH H EXAMPLE XVIII CH3 nC,,H H Zg: nC;,H (CH QFC-EFH, H C H The procedure of Example 11-15 is repeated, starting l1- H a w1th the appropriate benzothieno[3,2-d]pyr1m1dme, to C (CH=)= (C 3)(CH1): H provide in moderate yields the following compounds:

' EXAMPLE xix 4-Diethylamino-6-( m-aminophenyDpyrimidine dihydrochloride A solution of 24.5 g. (0.8 mole) of 4-diethylamino-6- (m-nitrophenyl)-pyrimidine hydrochloride, 62 g. of

stannous chloride and 370 ml. of 12 N hydrochloric acid contained in a 2 l 3.-.n.e cked flask is heated and stirred for 3 hours at 60 C. and then allowed to stir at room temperature overnight. The precipitate is ,filtered, washed with 12 N hydrochloric acid and dissolved in water. The aqueous solution is made basic with 10 sodium hydroxide solution and extracted with chloroform. Separation of the organic layer followed by drying over sodium sulfate and concentration j to dryness provides the crude product as an oil. The residue is redissolved in chloroform and .treated with gaseous hydrogen chloride until a p recipitate no longer forms. The product is filtered and dried, 19.1 g., m.p.

Mol wt.: Calcd. for 315.25. Found: 311 Equiv. wt.: Calcd. for 157.62. Found: 161 The free base, generated by treating an aqueous solution of the hydrochloride salt with a 10% sodium hydroxide solution, has a melting point of 78 C.' Anal. Calc. for c,;,H,,N,: c, 69.4; H,7.5; N, 231. Found: c, 69.0; H, 7.5; N, 23.2.

EXAMPLE XX The procedure of Example XIX repeatedifstarting with the compounds-of Examples XVlI and xvlll, to synthesize the following congeners:

, from ethyl acetate/methanol, 2.1 g., m.p. 236238 C. v

NH Position of I EXAMPLE XXI 4-Diethylamino-6-(m-acetylaminophenyl)pyrimidine hydrochloride An'al. Calcd. for C H ON HCl: C, 54.5, H, 5.6; N, 17.9. Found: C, 54.1; H, 5.6; N, 18.0. Anhydride Method .To';"5.6 g. (0.022 mole) of 4-diethylamino-6-(mamin'ophenyl)pyrimidine is slowly added, with cooling, 25 ml. of acetic anhydride. The resulting solution is stirred overnight at room temperature and is then di- EXAMPLE XXII luted with 500 ml. of ethyl acetate and treated with suf- Starting with the suitably Substituted ficient gaseous hydrogen chloride to Complete the P 6aminophenylpyrimidine and requisite reagents and cipitation of the desired product. The solvent and exfollowing the apropriate procedure method in Example cess acetic anhydride are removed under reduced pres- 5 XXI the following compounds are prepared:

Method X R R K m.p., C.

Anhydride 3-NHCOCH; nC3H1 nC H H 128-429 Anhydride 3-NHC0CH (CH,-), H 289-291 Anhydride 3NHCOCH; [1-C4Hg nC H H 193-195 Acid Chloride 3-NHC0C,H C,H C,H H 232-234 Acid Chloride 3NHCO(CH);CH; C H C H H 215-218 Acid Chloride 3NHCOCH(CH;) C 11 C H H 248-250 Acid Chloride 3NHCOCF C=H5 C H H 149151 Acid Chloride 3NHCOC;H C H; C1" 5 H 230-234 Acid Chloride 3-NHCO2CH3 Cg"; C H H 223 dec. Acid ChiOfidC 3-NHCO2C1H5 C2H5 CgH5 H 224 dec. Acid Chloride 3-NHs0 CH C H C,H H 225 Acid Chloride 3NHS0 CH, nC H n-C H, H 205 Anhydride 4--NHCOCH C 11 CgH5 H 272-275 dec. Anhydride 3-NHCOCH; CH CH Cg"; 215-217 Anhydride 3-NHCOCH; CzH5 C H CH; 174-176 Anhydride 3-NHCOCH C2H5 C2; C2; 136-138 Anhydride 3-NHC0CH n-C,H n-C H CH 198-202 Anhydride 3NHCOCH; C H C H; nC;,H 173-175 sure and the resldue washed from the flask with 20 ml. EXAMPLE XXIII of hexane/61h {acetate 235 The procedure of Example XXI IS repeated, using the It ProveS to be Identical that P p y the Acld 40 appropriate starting materials, to provide the following Chloride Method. analogs:

Method X R R R Anhydride 2NHCOCH; CzHs CgHs H Anhydride 2-NHCOCH; Cg; l1-C;H H Anhydride 2-NH- C H; l1C; H-, H

CO(CH CH Anhydride 2NHC0CH(CH C 11 C H H Acid Chloride 2-NHSO2CH3 C H C2H5 H Acid Chloride 3NHSogC3H5 CH CH C 11 Acid Chloride 3-NHCOCH CH -(CH H Anhydride 3NHCOCH H 2HQ CC;H H Anhydride 3'NHCOCH H 2-H,NSO,C.H. H Anhydride 4 NHCOCH cl-l CH; H Anh dridc 4NHCOCH CH, 1 CH CH H Acid Chloride 4NHCOCH(CH CH CH H Anhydride 4NHCOCH; v n-CJ-I, n-C H H Anhydride 4-NHCHO nC;,H-, nC;,H, H Acid Chloride 4-NHS0,,CH CH CH H Continued Method X RI R2 Acid Chloride 4'-1-1Hco',c H CH3 CH H Acid Chloride 4NHCOC5H5 nC H-, nC H H Anhydride 3-NHCOCH; CZHS CH5 CZHS Anhydride 3-NHCOCH; CH3 CH3 C H EXAMPLE XXIV Cominued 4-Diethylamino-6-(m-dimethylaminophenyl)pyrimi- X 2 3 2N(C H C H HO(CH H dme hydrochloride CHQ 2 2 H 3-N(CH C H H0 CH H To a solution of 2.6 g. (9.3 m moles) of 4- 3 Z Z Z 2 H 3-N CH CF CH H diethylammo-6-(m-aminophenyl)pyrlmidine hydro- E 3N(nC -,H1 )2 (CH 0(CH H chloride in 50 ml. of water is added 4.72 g. of sodium CZHS H carbonate followed by the slow addition of 2.74 g. of I-ESZ Sff' v 3-N(CH) cH cH CH methyl iodide. 3 N n i::H (Ii- 5H, H 5 H 5 The reaction mixture is heated to the reflux tempera- 2,322Ei $3 a? CEHH ll 2 3 3 4N(CH3)2 CZH HO(CH H ture for 6 hours, and 18 then cooled and extracted with 1 :Eg: Fem W43: 1 H n' r a 0 a CH H H chloroform The orga 1c laye 1s siep rated dried ver 4 N(C2H52 CH3 H sodium sulfate and evaporated 1n 'vacuo to a light z s) z s HO(CHm- H 5 1 )2 CZH5 HO(CH2)2 H brown Oll. Chromatographmg on a silica gel column 3H1)2 n. a 1 1 H and eluting with ethyl acetate provides the desired product as a light yellow oil which when dissolved in ethyl acetate and treated with gaseous hydrogen chloride provides the corresponding crude hydrochloride salt. Further purification is effected by recrystallization from methanol/ethyl acetate, 0.9 g., m.p. 170-l73 C.

EXAMPLE XXV Following the procedure of Example XXIV, and starting with the requisite 6-aminophenylpyrim idine and appropriate reagents, the following compounds are synthesized:

EXAMPLE XXVI Starting with 2Ebromothiophene and the requisite reagents, and following the procedure of Example I, the following congeners are prepared:

In a similar manner are prepared 4-ethylamino-5- methyl-6-(2-thienyl)-pyrimidine, 4-dimethylamino-5- ethyl-6-(2-thienyl)pyrimidine, 4-diethylamino-5-ethyl- 6-(3-thienyl)pyrimidine, 4-dipropyl-5-n-propyl-6-(3- thienyl)pyrimidine and 4-diallylamin0-5-ethyl-6-(3- thienyl)pyrimidine.

EXAMPLE XXVII 4-Diethylamino-6-(5-acetylamino-2- thienyl)pyrimidine hydrochloride A mixture of 28.26 g. (0.09 mole) of 4-diethylamino- 6-(5-nitro-2-thienyl)pyrimidine hdyrochloride and 35 g. of granular tin is treated, portionwise, with 75 ml. of concentrated hydrochloric acid. Cooling is necessary once the reaction has started. When the reaction has subsided, the clear hot solution is decanted from the unreacted tin and cooled in a salt-ice bath, and the resulting amine hydrochloride-stannic chloride complex which precipitates is filtered.

The complex is added to 75 ml. of water and 80 ml. of diethyl ether, and treated with sufficient sodium hydroxide to provide a pH of 9-10. The ether layer is separated, treated with 14.8 g. (0.135 mole) of acetic anhdride and heated to reflux for 3 hours. The resulting solution is washed with sodium hydroxide solution, separated, dried over sodium sulfate and concentrated to dryness. The product is dissolved in ethyl acetate and sufficient hydrogen chloride gas bubbled into the soltuion to precipitate the product as the hydrochloride salt. Recrystallization from isopropanol provides the pure product.

EXAMPE XXVIII Employing the procedure of Example XXVII, and starting with the appropriate reagents, the following compounds are synthesized:

with the appropriate reagents, to provide the following congeners in good yields:

EXAMPLE XXX The procedure of Example III is again repeated, using the requisite starting reagents, to provide, in good yields, the following products:

Continued EXAMPLE XXXlll The reduction-acylation procedure of Example XXXII is repeated, using the appropriately substituted 5 starting materials, to provide the following analogs:

i; R, R

Ar R, R. 'R. Z-benzofuryl (:F cH I C H r ..nc; H, RCONH Z-benzofuryl (CH;),N(CH')2C2H5 H I Z-benzofuryl (CH2)5. -H 3-benzofuryl CH3 CH3 'H 3-benzofuryl C H cyclo C H H 3 benzofuryl CZHS CH5 H 5 3benzofuryl C H V C2H5., iC;,H; 3-benzofuryl (C z)2 z)z H 3 benzofuryl iC;,H iC;,H I H 3-benzofuryl CH3 cyclo C H I H EXAMPLE XXXI Position I I of Substitution The procedure of Example I is repeated, starting with RCONH furyl R R1 R2 R3 the appropriate 2- or 3-halo benzo[b]thiophene and requisite reagents, to provide the following compounds 3 2 CZHS C255 CZHS H v v 3 2 CH CZH5 CZH5 H in moderately good yields: a 4 2 CH cF cH C,H H

I 4 2 nc H, CF,(:H C,H H I 5 2 c,H. CZHS 2 5 H s 2 iC;,H C H C,H H Ar N z 3 CH, CH C 5 H w 2 3 C H CF CH, CZH, H O 4 3 CH CF CH, c H H N 4 3 CH (CH H R3 4 3 C,H (CH2)= H 5 3 CH: CH; C H H N q I 5 3 C,H CF CH C H H 5 3 cH (CH2)5 H R! R2 5 2 CH3 CH3 CH3 CZH5 v 5 2 CZHS CH CH C H Ar R R R, 5 3 CH CH H C H 2-benzothienyl CH3 H H Z-benzothienyl c H, CH3 H 2-benzothienyl C H CH, CH, 2-bcnzothienyl CZHS CF;,CH2 H EXAMPLE XXXIV zbemmhlenyl H The procedures of Examples XIX and XXI are re- 2-benzothienyl CH3 cyclo C,H" H 3-benzothienyl CH CH3 H peated, using the requisite starting reagents, to provide 3-benzothienyl CH CH3 C2: the'following compounds in moderate yields: 3-benzothienyl CZHS HO(CH;-),- H 3-benzothienyl CZH5 CFJCH H 3-benzothienyl H HO2CC,H H 3-benzothienyl H I I H,NSO,CH, H 3-benzothienyl H i .-.)z 2)z. H 3-benzothienyl CH2=CHCH CHHHCH HI EXAMPLE XXXIIJ .RCONH 4Diethylamino-6-(5-acetylamino-2-furyl)pyriniidine hydrochloride 1 To a mixture of 2.62 -g. (0.0! I 'mole) of 4- I diethy]amino-6-(5-nitro-2-furyl)pyrimidine and. aluminum amalgam, preapred from 4.0 g. of aluminum turnings,in ml. of diethyl ether is added 4 ml. of water. Acetic anhydride (2.0 g.; 0.02 mole) is added dropwise during the ensuing reaction which-is maintained by 60 I heating the reaction vessel in a warm water bath. The F Y ..of Substitution ether is filtered and the filtrate dried over sodium sul- RCONH pyndyl- R R, R2 R3 fate; Removal of the solvent under reduced pressure I provides the crude product. The residue ;is.dissol'ved in 3, g g3: g

. :i 2 2 ethyl acetate and treated with gaseous hydrogen'chlo- 4 czHs H ride until a precipitate no longer forms. The resulting g Eg g z gas; 3

. 3 2 5 2 5 hydrochloride salt is further pur fied by several recrys 4 3 CH3 CZHS CzHs H tallizations from methanol/hexane. I 5 3 CH C,H, C H H -Continued EXAMPLE XXXV 4Diethylamino-6-(2-furyl)pyrimidine hydrochloride RCONH Crude 4-dlethylamlno-6-(2-furyl)pyrlmldlne (3.2 g.; 0.015 mole), obtained by repeating the procedures of Example III, is dissolved in 25 ml. of dry ethyl acetate and treated with 1.44 g. (0.016 mole) of oxalic acid. N The resulting solution is warmed briefly on a steam bath, and is then cooled in a salt-ice bath. The resutling N oxalate salt is filtered, dried and recrystallized from methanol/hexane. The purified oxalate is dissolved in v I 2 a minimum amount of water and the pH adjusted to 9 of iigga using a 5% sodium hydroxide solution. Ethyl acetate is RCONH pyridyl R Rl R2 R3 added and the free base rapidly extracted. The organic s 3 C H H phase is dried over sodium sulfate and treated with suf- 3 1 cpacHz H ficient gaseous hydrogen chloride to completely pre- 2 2 91a gy C6 L cipitate the hydrochloride salt, WhlCh is filtered, wash- 2 4 njcHa i h: H ed with acetone and dried, m.p. l79180 C. 2 4 iC H-, C,H 6 H H 2 4 CH CF -,CH C H H 3 4 CH (CH )O(CH H 3 4 z s z s z 2 2 2 H EXAMPLE XXXVI 3 4 H z s z s H i g g E 3 Starting with the appropriately substituted reagents- 2 5 2 S 2 5 2 u a a 5 2 n C4HB CHa C2145 and employing the respective procedures indicated, the 5 2 e H a a a 1 following products are synthesized:

X! X, R, R2 R;, R. Procedure 3 cH c0 H CH CH H H Exam le III 3CH;|CO H CgH5 C=H H H Example III 3CH;,CO H (CH;) H H Example III 4CH -,CO H CFJCH CZH, CH; H Example III 4CH;,CO H HO(CH,)2 cgH5 CH; H Example III 4-cH,c0 H H HO;CC.H, CH H Exam le III 4CH;,CO H (CH,)4 CH; H Example III 3,4 CH=O1 C H CH5 H H Example I 3,4CHO2 HO(CH,)2 C, .H 'J H H Example I 3,4-CH,O CF=CH1 2H5 H H Example I 3,4-CH=O, CH=CHCH2 C H H H Example I 3N0, Cl C,H5 ,H, H H Example XVI 3- 4-Cl CF3CH, C,H,-, H H Example XVI 3' 4-OCH3 CF CH, c H H H Example XVI 3NO 4-OCH;, CIHS- 2H,, H H Example XVI 3-NO2 4F (CH=)5 H H Example XVI 3- 4-Cl CgH5 C H H H Example XIX 3 4-Cl CF;,CH c,H H H Exam le xlx 3- 4-OCH; CFJCHZ C2H5 H H Example XIX 3- 4-OCH; C H C H H H Example XIX a-NH 4F (CH,), H H Example XIX 3CH;CONH 4-Cl C=H CH; H H Example XXI 3--CH3CONH 4Cl CF CH C2H5 V H H Example XXI 3CH;CONH 4-oCH, CF CH C,l-l H H Example XXI 3CH;,CONH 4OCH;, C,H5 C H H H Example XXI 3-CH3CONH 4-F 7 (CH2), H H Example XXI 3--CH O CNH 4CI C H C l-I H H Example XXI 3C2H |,O,CNH 4OCH; CgH5 C Hs H H Example XXI 3C,H,O2CNH 4-F (CH),', H H Example XXI 3CH;,CONH H C H c H CH CH Exam le I 3CH;,CONH H C,H CF CH, CH3 CH3 Example I 3-CH=,CONH H (3 H c H (:,H Example l 3(CH ),NCO H C,H C H H H Example XXI 3(C,H )NCO H C,H C H H H Example XXI EXAMPLE xxxvu 1-[ 3-( 6-Diethylamino-4-pyrimidinyl )phenyl ]-3- phenylurea hydrochloride EXAMPLE XXXVlll The procedure of Example XXXVll is repeated, using the appropriate starting reagents, to provide the following analogs in good yields:

EXAMPLE XXXIX Tablets A tablet base is prepared by blending the following ingredients in the proportion by weight indicated:

Sucrose. U.S.P. 80.3 Tapioca starch 13.2 Magnesium stearate 6.5

Into this tablet base there is blended sufficient 4- diethylamino-6-(m-acetylaminophenyl)pyrimidine hydrochloride to provide tablets containing 20, 100 and 250 mg. of active ingredient per tablet. The compositions are each compressed into tablets, each weighing 360 mg., by conventional means.

EXAMPLE XL Capsules A blend is prepared containing the following ingredients:

Calcium carbonate, U.S.P. Dicalcium phosphate Magnesium trisilicate. U.S.P. Lactose, U.S.P.

Potato starch,

Magnesium stearate A Magnesium stearate B To this blend is added sufficient 4-diethylamino-6- (m-dimethylaminophenyl)pyrimidine hydrochloride to provide capsules containing 20, 100 and 250 mg. of active ingredient per capsule. The compositions are filled into conventional hard gelatin capsules in the amount of 350 mg. per capsule.

EXAMPLE XLI lnjectable Preparation One thousand grams of 4-diethylamino-6- phenylpyrimidine hydrochloride are intimately mixed and ground with 2500 grams of sodium ascorbate. The ground dry mixture is placed in vials and sterilized with ethylene oxide after which the vials are sterilely stoppered. For intravenous administration, sufficient water is added to the materials in the vials to form a solution containing 10 mg. of active ingredient per milliliter of injectable solution.

EXAMPLE XLII Suspension A suspension of 4-diethylamino-6-(m propionylaminophenyl)pyrimidine is prepared with the following composition:

Effective ingredient 25.00 g. Aqueous sorbitol 74129 g. Glycerine, U.S.P. 18535 g. Gum acacia (10% solution) 100.00 ml. Polyvinylpyrrolidone 0.50 g.

Distilled water Sufficient to make 1 liter To this suspension, various sweeteners and flavorants are added to improve the palatability of the suspension. The suspension contains approximately 25 mg. of effective agent per milliliter.

EXAMPLE XLllI Solution A solution of 4-diethylamino-6-(p-methoxyphenyl)- pyrimidine hydrochloride is prepared with the following composition:

Effective ingredient 30.22 grams Magnesium chloride hexahydrate 12.36 grams Monoethanolamine 8.85 ml. Propylene glycol 376.00 grams Water, distilled 94.00 rnl. 

1. A METHOD OF INHIBITING PLATELET AGGREGATION IN THE BLOOD OF HUMANS WHICH COMPRISES ADMINISTERING TO SAID HUMANS AN EFFECTIVE AMOUNT SUFFICIENT TO INHIBIT PLATELET AGGREGATION IN THE BLOOD OF THE HUMANS OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THOSE OF THE FORMULA:
 2. The method of claim 1 wherein R1 is ethyl, R2 is alkyl containing from 1 to 4 carbon atoms and R3 is hydrogen.
 3. The method of claim 2 wherein said compound is 4-diethylamino-6-(p-methoxyphenyl)pyrimidine.
 4. The method of claim 2 wherein said compound is 4-diethylamino-6-phenylpyrimidine.
 5. The method of claim 2 wherein said compound is 4-(ethyl-n-propylamino)-6-phenylpyrimidine.
 6. The method of claim 2 wherein said compound is 4-diethylamino-6-(2-thiEnyl)pyrimidine.
 7. The method of claim 2 wherein said compound is 4-diethylamino-6-(m-dimethylaminophenyl)pyrimidine.
 8. The method of claim 1 wherein Ar is phenyl, R1 is alkyl containing from 1 to 4 carbon atoms and R3 is hydrogen.
 9. The method of claim 8 wherein said compound is 4-(ethyl(2-hydroxyethyl)amino)-6-phenylpyrimidine.
 10. The method of claim 8 wherein said compound is 4-ethylamino-6-phenylpyrimidine.
 11. The method of claim 1 wherein Ar is phenyl, R1 is 2,2,2-trifluoroethyl and R3 is hydrogen.
 12. The method of claim 11 wherein said compound is 4-(2,2,2-trifluoroethylamino)-6-phenylpyrimidine.
 13. The method of claim 1 wherein R1 and R2 are each ethyl and R3 is alkyl containing from 1 to 3 carbon atoms.
 14. The method of claim 13 wherein said compound is 4-diethylamino-5-methyl-6-phenylpyrimidine.
 15. The method of claim 13 wherein said compound is 4-diethylamino-5-ethyl-6-phenylpyrimidine. 